1. Field of the Invention
The present disclosed technology relates generally to a system for steering and operating forklift trucks, and more specifically to steering and operating a narrow-aisle, articulated forklift truck using a hydraulic actuator.
2. Description of the Related Art
A typical narrow-aisle articulated forklift truck (or “forklift”) comprises front and rear chassis sections each having a pair of wheels on a respective common axis. The rear wheels provide drive-motion to the forklift truck, while the front wheels are non-driven and steer the truck. The chassis sections are pivoted together about a vertical axis so that the front chassis section, including a mast, can be turned at an angle of approximately 90° each way (preferably 180°-205° total range of movement) relative to the rear chassis section to allow the truck to insert loads into, and remove loads from, the faces of the aisle.
Without limitation on the generality of useful applications of the present invention, an exemplary use consists of loading and unloading palletized inventory in narrow-aisle facilities, such as warehouses. Steering with the front wheels is generally preferred for such applications because rear-wheel steering forklifts generally have relatively large turning radii and are thus ill-suited for loading and unloading storage bins in narrow aisles, such as those found in many warehouses and other storage facilities. Narrow-aisle, articulated forklift trucks, on the other hand, allow the mast-portion of the forklift to turn independently from the body of the truck, which allows the operator to load or unload material positioned perpendicular to the aisle along which the truck is traveling. Typical narrow-aisle trucks are capable of rotating the front chassis mast section at least 90° each way relative to a direction of travel along a warehouse shelf aisle.
A problem condition associated with many previous articulated forklift trucks is the articulating joint between the front and rear chassis sections. An electric or hydraulic motor is typically used to steer the forklift truck by rotating the front chassis section relative to the rear section. Because the front chassis includes the mast, which is subjected to heavy loads, the rotation motor and connection are high-wear components which can be expensive to replace. What is needed is an articulated forklift truck capable of maneuvering in narrow aisles and handling heavy loads while minimizing the wear on the articulating component of the truck.
Heretofore there has not been a forklift truck embodying the capabilities of the invention presented herein.